Bending and straightening mechanism for mine roof bolts

Abstract

A method and apparatus for successively bending and straightening a bolt shank and the like for insertion into a bolt hole is characterized by a readily transportable compact device having inner and outer spaced cooperating rollers engageable with diametrically opposed surfaces of the shank so that when the cooperating rollers are simultaneously rotated along a predetermined bending path the shank will be bent through a corresponding curvature and in a direction aligned with a bolt hole into which the shank is to be inserted. A straightener roll is disposed in the path of the shank as it becomes aligned with the bolt hole to straighten the shank prior to advancement into the hole. In the method of successively bending and straightening a bolt shank in accordance with the present invention, the shank is positioned at a substantial angle of 90.degree. to the longitudinal axis of the bolt hole, the leading end of the shank is bent in a direction towards the entrance of the hole until it becomes axially aligned with the hole, and the shank is progressively bent along its length in a direction towards the hole followed by progressively straightening of the shank as it advances into axial alignment with the hole while continuously feeding the entire length of the shank into the bolt hole.

Dependencies are inferred from the claim text.